Planets are Complex Systems:

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• Planets are Complex Systems
• Earth and Mars
• July 17, 2004
• Presented to teachers in TRUST
• by Denton S. EbelAssistant Curator,
  MeteoritesDepartment of Earth and Planetary
  Sciences

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Planets Complex Interacting Systems Systems -
shoelaces in a shoe, a car engine, the subway
system, your body, New York City, a planet, the
solar system. Interacting - parts of the system
interact with each other bigger systems have
many more interactions actions cause
reactions. Complex - longer times, bigger
systems, varied parts, less predictable
interactions.
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Comparative Planetology Themes Energy where it
comes from (sources) where it goes
(sinks) energy transfer convection, radiation,
conduction, gravitation, chemical
reactions Chemical Cycles rock, water, carbon,
nitrogen Time scales How fast are chemical
cycles?
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Our Solar System
Asteroid belt (meteorites)
Pluto-Kuiper belt (short period comets)
Gas giants ltlt gtgt Rocky planets
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Most abundant element in the Earth Oxygen
(O) Followed by Iron (Fe), Magnesium (Mg),
Silicon (Si)
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Convection Earth cut-away cartoon on left Boiling
beaker on right (image taken from
published literature has been removed here)
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From http//www-spof.gsfc.nasa.gov/Education/Int
ro.html See also Earth Machine p.71
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Earth Plates Volcanoes (image taken from
published literature has been removed here)
Plates and Volcanoes
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The Rock Cycle and Tectonic Plate Boundaries
artist Jose F. Vigil, U.S. Geological Survey
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Mars, Relative to Earth Smaller size
Faster cooling gt mostly solid core gt very weak
magnetic field Lower gravity gt loss of
atmosphere to space No tectonics gt limited
chemical cycling of elements Location Less
solar irradience Higher eccentricity of orbit gt
less stable long-term climate
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Planetary Oceans and Atmospheres Elements H,
C, N, O Sources original material (outgassing),
comets Sinks chemical and biological
reactions Interactions (micro)-biosphere,
carbon cycle Energy gravity, solar heat,
chemical reactions
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(Earth)
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Mississippi River watershed
movie from NASA/Goddard Space Flight Center
Conceptual Image Lab
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Cities warm the air over cities, causing enhanced
rainfall
movie from NASA/Goddard Space Flight Center
Conceptual Image Lab
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Ocean Carbon Cycle (slow)
movie from NASA/Goddard Space Flight Center
Conceptual Image Lab
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Land Carbon Cycle (fast)
movie from NASA/Goddard Space Flight Center
Conceptual Image Lab
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Ocean Conveyer Belt (image taken from
published literature has been removed here)
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Biosphere 1 EARTH
The biosphere is that part of a planet's outer
shell including air, land, and water within
which life occurs, and which biotic processes in
turn alter or transform. From the broadest
geophysiological point of view, the biosphere is
the global ecological system integrating all
living beings and their relationships, including
their interaction with the elements of the
lithosphere (rocks), hydrosphere (water), and
atmosphere (air). Earth is the only place where
life is known to exist. This biosphere is
generally thought to have evolved beginning at
least some 3.5 billion years ago.
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• Roles of Water (short list)
• Heat transfer is mediated by water on Earth
• All life we know of on Earth requires water
• Water is a major greenhouse gas
• Thermostatic control (high heat capacity)
• Dissociates in ultraviolet light to make ozone
• - CO2 in water dissolves surface rocks

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• Evidence for Water on Mars
• - Ice cap spectra show water ice plus CO2 ice
• Crater features change with latitude gt ground
  ice
• Outflow channels gt huge floods
• Gullies gt recent ground water outflows
• Frost gt dry ice (CO2), not water!
• Martian meteorites gt recent water-rock
  interaction
• - Mars Exploration Rovers gt water-deposited
  rocks
• - Satellite measurements of D/H in atmospheric H2

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Nakhla (fell, Egypt 1911) A basaltic igneous rock
now known to come from Mars.
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Highs (red, white) and Lows (blue) of Mars
Spirit
Northern lowlands
Southern highlands
Opportunity
Olympus Mons
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Mars North Pole
3D reconstruction from Mars Orbiter Laser
Altimeter (MOLA) data (Mars Global Surveyor,
spring and summer of 1998) 750 miles (1,200
kilometers) across, with a maximum thickness of
1.8 miles (3 kilometers)
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Arctic Vortex
movie from NASA/Goddard Space Flight Center
Conceptual Image Lab
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Tiu Vallis Source region, collapse structures
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Ares Vallis and Tiu Vallis evidence for water
flow
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Mars crater with gullies (PIA04408)
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Gullies (formed by water ?) are younger than
dunes (left), freeze/thaw polygons (middle), and
deposition of fine dust (right).
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Robot Geologist
Spirit Rover on Mars, May 2004 (landed Jan 3,
2004)
Apollo 11 Astronauts on Moon July 20, 1969
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Robot geologist looks for water on Mars
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Opportunity Rover Views of Crater Rim Outcrop
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lt 2.2 cm (0.8 inch) gt
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Cycles on Titan Saturns major moon, visited by
Cassini mission Liquid/solid methane
(CH4) Source original material
outgassing Forces solar heating.
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The Cassini-Huygens Mission to Saturn
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Huygens Probe Scientific Objectives

• Determine Titans atmospheric composition
• Investigate energy sources for atmospheric
  chemistry
• Study aerosol properties and cloud physics
• Measure winds and global temperatures
• Determine properties of Titan surface and infer
  internal structure
• Investigate the upper atmosphere and ionosphere

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(courtesy of D. Grinspoon, 2005)
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Huygens probe landing site, imaged by Cassini.
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This is one of the first raw images returned by
the ESA Huygens probe during its successful
descent. It was taken from an altitude of 16.2
kilometres with a resolution of approximately 40
metres per pixel. It apparently shows short,
stubby drainage channels leading to a shoreline.
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San Francisco
Titan
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• Huygens Results
• engineering a fantastic success
• surface T 93.8 K (-180 C)
• low topography
• landforms precipitation, erosion, abrasion
• no noble gases in atmosphere except 40Ar
• 15N/14N about 3x Earth
• CH4 volatilizes easily at surface
• surface thin hard crust above porous material
• water ice in surface rocks

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• Useful Links
• General
• http//www.amnh.org/education/online/ (AMNH
  online resources)
• http//nsdl.org/ (National Science Digital
  Library)
• http//svs.gsfc.nasa.gov/stories/ (great
  visualizations of data)
• Earth System Science
• http//www.dlese.org/library/ (Digital Library
  for Earth System Education)
• http//www.physicalgeography.net/fundamentals/cont
  ents.html (basic text)
• http//eol.jsc.nasa.gov/Education/ESS/ (college
  level NASA matarial)
• http//esse21.usra.edu/ESSE21/ (college level
  NASA matarial)
• http//www.nasa.gov/audience/forkids/home/index.ht
  ml (NASA for kids)
• http//kids.earth.nasa.gov/ (NASA for kids)
• http//science.hq.nasa.gov/info/sitemap.html
  (NASA overall science sites map)
• http//earthobservatory.nasa.gov/Library/ (NASA
  Earth Observatory home)
• Planetary Images
• http//astrogeology.usgs.gov/Projects/BrowseTheSol
  arSystem/
• http//earth.jsc.nasa.gov/sseop/efs/
• http//nssdc.gsfc.nasa.gov/photo_gallery/
• http//images.jsc.nasa.gov/

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• Geochemical Cycles
• http//www.carboncyclescience.gov/ (NASA
  policy-level material)
• http//ga.water.usgs.gov/edu/ (excellent
  overview)
• http//www.physicalgeography.net/fundamentals/9s.h
  tml (Nitrogen cycle)
• Atmosphere
• http//asd-www.larc.nasa.gov/SOLAR/learningindex.h
  tml (SAGE outreach)
• http//www.giss.nasa.gov/edu (news links to
  resources)
• Water
• http//www.nesc.wvu.edu/ndwc/ndwc_Kids_DWinfo.htm
  (about drinking water)
• http//www.uga.edu/publichealth/ehs/students/activ
  ities/ehsclub/links.htm
• (Georgia watershed site useful links)
• http//www2.ctic.purdue.edu/KYW/ (know your
  watershed)
• Rocks
• http//volcano.und.edu/ (U. N. Dakota volcano
  site)
• http//earthquake.usgs.gov/ (with links to kid
  sites)
• http//www2.nature.nps.gov/geology/USGSNPS/misc/pd
  fdocs.html (resources)
• http//pubs.usgs.gov/gip/dynamic/dynamic.html
  (online text)
• http//www.amnh.org/education/resources/ (click
  Earth Science)
• http//chem.tufts.edu/AnswersInScience/
  (Evolution age of the Earth)

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fin.
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fin.
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Extra images follow....
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Frost (CO2) seen by Viking 2 Lander (ca. 1978)
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Satellite Imaging of Earth Using Light Pulses
to Measure Changes in Vegetation Thickness,
Cloud Thickness, Ice Thickness
movie from NASA/Goddard Space Flight Center
Conceptual Image Lab
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Gully with (left) and without (right) CO2 snow
(PIA04270)
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Bonneville and Beyond
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Inner Solar System
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Brief History of Planets Earth is
special Partially molten ball of rock and
gases, 4.6 G years ago Differentiation De-gas
sing of H, He, C, N, O to the surface Core
formation Cooling gt Condensation of water,
chemical weathering Development of ozone layer
Continents and oceans form Anaerobic bacteria
(cyanobacteria) begin work (3.8 G
years) Present oxygen levels reached about 400
M years ago Rise of the human race, exploration
of other planets
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Arm and Scraping Tool, RAT
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Hematite concretions (Fe2O3) Likely deposited by
water.
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Vugs Holes left by sulfate mineral crystals
? Sulfates deposited by water.
Crystals dissolved from rock by water.
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Comet P/Halley (ESA Giotto Mission)
951 Gaspra
Comet Wild 2 (US Stardust Mission)
Deimos
Phobos
Comet Borrelly
Asteroid Ida and its moon Dactyl
Comet C/Hale-Bopp
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